How much does it cost to fix boiler error code 166?

Typical repair cost for the boiler 166 fault is £120-220 including labour.

166 High

Boiler Fault Code 166

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code 166 appears across 1 boiler brand and 26 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has detected an issue with the way it is venting or drawing air, causing it to shut down for safety. (As reported on Baxi EcoBlue)

Pick your boiler brand for the 166 fix

Baxi 166 26 models

Source

Information for the 166 fault code is sourced from the official service / installation manual for each model that displays it. Read more about how we source fault codes →

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026